Abstract
Nanocrystallites of pure and mixed ternary ferrites, NiFe2O4 (NiF), CuFe2O4 (CuF), CoFe2O4 (CoF), Ni0.5Cu0.5Fe2O4 (CuNiF), Ni0.5Co0.5Fe2O4 (NiCoF), and Cu0.5Co0.5Fe2O4 (CuCoF) were prepared using the auto-combustion method employing urea as a fuel. The obtained materials were investigated by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron miscroscopy (TEM), scanning electron microscopy (SEM), and BET techniques. The elemental composition of the prepared samples was checked by X-ray fluorescence (XRF) analysis. XRD indicated that the as-synthesized samples exhibit a pure spinel crystal structure. The samples have crystallite sizes ranged from 12 to 47 nm. SEM and TEM analyses showed almost spherical morphology for all ferrite particles. The M-H curves recorded using the VSM (vibrating sample magnetometer) technique showed ferromagnetic hysteresis loop for all the samples investigated. The ferrite samples were tested to be used as a supercapacitor electrode material. It is found that the measured specific capacitance of the ferrite electrodes increases according to CuCoF > NiCoF > CoF > NiCuF > CuF > NiF. The CuCoF sample showed the greatest specific capacitance of 220 F/g at discharging current density l of A/g with, an energy density of 34.72 Wh/kg and power density of 605 W/kg. The magnetic properties were also measured for the obtained nanoparticles.